A major drug trafficking investigation announced by Citrus Heights police Wednesday has so far netted $2.5 million in marijuana, seven firearms and hundreds of thousands of dollars in cash, according to authorities.

Chief Christopher Boyd said the seizure – much of it coming from a home in El Dorado Hills – was the largest in the department’s eight-year history.

“This is really a sophisticated criminal enterprise we’ve uncovered,” he said in a news conference.

Police have arrested two suspects in connection with the case: Jeremy Zahn, 31, of Citrus Heights and Lindsey Loya, 23, of La Verne.

Detectives have obtained an arrest warrant for a third suspect they did not publicly identify. They said they expect an arrest soon.

The case began with a March 17 traffic stop involving Zahn, who is on Post-Release Community Supervision. Part of the state’s prison realignment plan, PRCS requires county probation officers to monitor offenders who, before realignment, would have been watched by state parole officers.

During a probation search, the patrol officer – described by Boyd as “alert” – found evidence of drug trafficking and informed detectives.

The ensuing investigation led to surveillance, another traffic stop involving Zahn and searches of two residences. In total, police say they uncovered 858 pounds of pot with an estimated street value of $2.5 million; seven firearms, two of which were illegal and one of which had been stolen from a federal Bureau of Prisons employee; and almost $465,000 in cash.

Much of the haul came from what police described in an arrest warrant affidavit as a “stash house” in El Dorado Hills. In one room off the basement, hidden from view by plywood, police found several large black plastic trash bags full of marijuana, according to the affidavit. Police also found packaging materials in the home.

In the second traffic stop involving Zahn, police pulled from his car boxes tightly wrapped in plastic and addressed to people out of state, according to the warrant request. Police declined to name the states involved in the investigation.

“From my training and experience, subjects who mail illegal substances … will warp the illegal substances so investigators would not be able to smell the illegal substances or know what contents are inside of the boxes,” Detective Austin Azevedo wrote in the affidavit.

The materials used to package the pot found in the car matched the materials found in the El Dorado Hills home, Azevedo wrote.

Detectives are still investigating the scope of the trafficking operation, but said they believe the El Dorado Hills portion began in September. That’s about the time that Zahn was released from custody on PRCS status, police said.

To be released on PRCS status, an offender’s last conviction cannot be violent, sexual or “serious,” as defined by state law. It was not immediately clear Wednesday what Zahn’s last offense was, though Sacramento Superior Court records show he pleaded no contest to a felony count of possession of stolen property in July 2011. Court records do not include information about his sentence for that crime.

Zahn has one other previous case in Sacramento County. In April 2010, he pleaded guilty to a misdemeanor charge of attempted forgery of a prescription and was sent to a drug diversion program, according to online records.

Zahn has been charged with transportation of and possession for sales of marijuana and violation of his release conditions. He is being held at Sacramento’s Rio Cosumnes Correctional Center, where he is ineligible for bail. He could not be reached for comment.

Loya was arrested in Los Angeles County. Once transferred to Sacramento, she is expected to be charged with transportation of and possession for sale of marijuana, according to police. She also could not be reached for comment.

A Citrus Heights police task force that focuses on offenders under supervision – such as probationers, parolees and people on PRCS – handled the trafficking investigation, with help from the Bureau of Alcohol, Tobacco, Firearms and Explosives and the U.S. Postal Inspection Service. The police task force also includes Sacramento County probation officers and a Folsom police officer.

Lee Seale, chief of the Probation Department, said law enforcement officers statewide knew that the prison realignment plan would pose a challenge.

“What today shows is that locals have stepped up to meet this challenge,” he said.

Seale said the Citrus Heights police task force has made 60 arrests and conducted 200 searches since its creation.